1. Field of the Invention
This invention relates to a process and apparatus for the care of contact lenses, wherein the lenses are treated in a liquid bath.
2 Description of Related Art
The increasing use of contact lenses has created an increasing demand for lens care processes that can be carried out by the contact lens user. Known processes for cleaning, disinfecting and sterilizing contact lenses which the user can perform at home or while traveling have the disadvantages of requiring relatively long treatment times of from twenty minutes to more than four hours, of exhibiting difficulty in handling the apparatus and/or of involving complicated procedures.
U.S. Pat. Nos. 4,009,777 and 4,444,307 and German Patent Publication No. OS 31 45 468, for example, describe containers for cleaning contact lenses comprising cup-like holders for the lenses that are usually mounted on a cover member. These containers differ from one another largely in the design of the cups and have the disadvantage that they do not include means for accelerating the cleaning process.
To accelerate the cleaning process, it is proposed in U.S. Pat. Nos. 4,256,952, 4,270,309 and 4,369,355, European Pat. No. 21 828 and British Patent No. 2,072,509, to provide contact lens containers with heating means. These containers employ temperatures of up to 100.degree. C. in the liquid bath to sterilize the lenses. Containers employing these temperatures are not universally usable since such temperatures are suitable for so-called soft contact lens but not for so-called hard contact lens. In addition, with contact lens that have not been properly cleaned, high temperatures can result in deposits, particularly protein deposits, being fixed to the surface of lenses which makes cleaning more difficult.
Ultrasonic cleaning apparatus for contact lenses has also been provided as shown for example in German Patent Publication No. OS 29 25 750 and 05 31 06 519, in European Patent No. 31 152 and in UK Pat. No. 2,507,353. However, because of complicated and costly manufacture, ultrasonic cleaning apparatus is expensive and not easy to use at home or while traveling. In addition, the relatively severe mechanical stresses produced by ultrasonic treatment can damage the lenses.
U.S. Pat. No. 3,623,492 and German Patent Publication No. OS 34 10 400 describe contact lens cleaners comprising containers with lens holders designed to rotate in the cleaning solution and thus to promote washing of the cleaning liquid over the surfaces of the contact lens. In cleaners of these designs no Provision has been made for agitating the liquid bath to accelerate the dissolution of, for example, a tablet or a powder of a cleaning or sterilizing material. In addition, this type of cleaner is designed for manual use with the container covers being provided wit a rotatable portion connected to the contact lens holder so that, when the cover is turned, it rotates the lens holder. Since use of this arrangement is a very tiresome procedure, the cleaning cycle is apt to be stopped before the lenses are completely cleaned.